Two stage trigger, clamp and cut bipolar vessel sealer

ABSTRACT

A surgical instrument includes a handle assembly and an end effector. The handle assembly includes a trigger, a push plate coupled to the trigger, wherein actuation of the trigger rotates the push plate, a clamp plate operably coupled to the push plate, wherein actuation of the trigger to a first rotation rotates the clamp plate, and a firing plate operably coupled to the push plate, wherein actuation of the trigger between the first rotation and a second rotation rotates the firing plate. The end effector includes a jaw assembly which includes a first jaw member and a second jaw member, wherein rotation of the clamp plate transitions the jaw assembly between an open configuration and an approximated configuration by moving at least one of the first jaw member and the second jaw member relative to the other one of the first jaw member and the second jaw member.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 14/227,699, entitled TWO STAGE TRIGGER, CLAMP AND CUT BIPOLAR VESSEL SEALER, filed Mar. 27, 2014, the entire disclosure of which is hereby incorporated by reference herein.

BACKGROUND

The present disclosure is related generally to electrosurgical devices with various mechanisms for clamping and treating tissue. In particular, the present disclosure is related to electrosurgical devices with two-stage triggers.

While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

FIGURES

The novel features of the embodiments described herein are set forth with particularity in the appended claims. The embodiments, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows:

FIG. 1 illustrates one embodiment of a surgical instrument comprising a two-stage trigger;

FIG. 2 illustrates one embodiment of the surgical instrument of FIG. 1 with a left handle housing removed;

FIG. 3 illustrates a partial view of the embodiment in FIG. 2;

FIG. 4 illustrates one embodiment of a trigger assembly of the surgical instrument in FIG. 1;

FIG. 5 illustrates an exploded view of the surgical instrument of FIG. 1;

FIG. 6 illustrates one embodiment of the surgical instrument of FIG. 1 having a trigger in a partially rotated position;

FIG. 7 illustrates one embodiment of a cam path plate and a plunger when the trigger is in the partially rotated position of FIG. 6;

FIG. 8 illustrates one embodiment of the surgical instrument of FIG. 1 having the trigger rotated to a full clamp;

FIG. 9 illustrates one embodiment of the camp path plate and the plunger when the trigger is rotated to a second actuated position in accordance with certain embodiments described herein;

FIG. 10 illustrates one embodiment of the surgical instrument of FIG. 1 having the plunger in a locked position;

FIG. 11 illustrates one embodiment of the trigger assembly of the surgical instrument of FIG. 1 when the trigger is rotated to an intermediate actuated position in accordance with certain embodiments described herein;

FIG. 12 illustrates one embodiment of the surgical instrument of FIG. 1 having the trigger rotated to a fired position;

FIG. 12A illustrates one embodiment of a cam path of the surgical instrument of FIG. 1;

FIG. 13 illustrates one embodiment of the trigger assembly of the surgical instrument of FIG. 1 in a partial return position;

FIG. 14 illustrates one embodiment of the surgical instrument of FIG. 1 comprising a two-stage bypass switch;

FIG. 15 illustrates one embodiment of the trigger assembly of the surgical instrument of FIG. 1 in a bypass position;

FIG. 16 is a graph illustrating one embodiment of a force to fire the surgical instrument of FIG. 1 from an open to a fully fired position;

FIG. 17 is a graph illustrating one embodiment of a mechanical advantage of the trigger as the trigger is rotated from an initial position to a full clamp position;

FIG. 18 is a graph illustrating one embodiment of a mechanical advantage of the trigger as the trigger is rotated from the full clamp position to a fired position;

FIG. 19 is a graph illustrating one embodiment of a clamp load while the jaw assembly is maintained in a partially open configuration;

FIG. 20 is a graph illustrating one embodiment of a clamp load while the jaw assembly is maintained in a fully open configuration;

FIG. 21 illustrates one embodiment of an energy button of the surgical instrument of FIG. 1;

FIG. 22 illustrates one embodiment of an electrosurgical control circuit of the surgical instrument of FIG. 1; and

FIG. 23 illustrates one embodiment of the surgical instrument of comprising an electrosurgical energy system of the surgical instrument of FIG. 1.

DESCRIPTION

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols and reference characters typically identify similar components throughout the several views, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented here.

The following description of certain examples of the technology should not be used to limit its scope. Other examples, features, aspects, embodiments, and advantages of the technology will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the technology. As will be realized, the technology described herein is capable of other different and obvious aspects, all without departing from the technology. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings, expressions, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, expressions, embodiments, examples, etc. that are described herein. The following-described teachings, expressions, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.

Before explaining the various embodiments of the surgical devices having two-stage triggers in detail, it should be noted that the various embodiments disclosed herein are not limited in their application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. Rather, the disclosed embodiments may be positioned or incorporated in other embodiments, variations and modifications thereof, and may be practiced or carried out in various ways. Accordingly, embodiments of the surgical devices with two-stage triggers disclosed herein are illustrative in nature and are not meant to limit the scope or application thereof. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the embodiments for the convenience of the reader and are not to limit the scope thereof. In addition, it should be understood that any one or more of the disclosed embodiments, expressions of embodiments, and/or examples thereof, can be combined with any one or more of the other disclosed embodiments, expressions of embodiments, and/or examples thereof, without limitation.

Also, in the following description, it is to be understood that terms such as front, back, inside, outside, top, bottom and the like are words of convenience and are not to be construed as limiting terms. Terminology used herein is not meant to be limiting insofar as devices described herein, or portions thereof, may be attached or utilized in other orientations. The various embodiments will be described in more detail with reference to the drawings.

Turning now to the figures, FIG. 1 illustrates a surgical instrument 2 comprising a two-stage trigger assembly 8. The two-stage trigger assembly 8 is configured to clamp and fire an end effector 10 coupled to the surgical instrument 2. The surgical instrument 2 comprises a handle assembly 4, a shaft assembly 12, and an end effector 10. The shaft assembly 12 comprises a proximal end and a distal end. The proximal end of the shaft assembly 12 is coupled to the distal end of the handle assembly 4. The end effector 10 is coupled to the distal end of the shaft assembly 12. The handle assembly 4 comprises a pistol grip 18. The handle assembly 4 comprises a left handle housing shroud 6 a and a right handle housing shroud 6 b. The two-stage trigger assembly 8 comprises a two-stage trigger 9 actuatable towards the pistol grip 18. A rotatable shaft knob 20 is configured to rotate the shaft assembly 12 with respect to the handle assembly 4. The handle assembly 4 further comprises an energy button 22 configured to provide electrosurgical energy to one or more electrodes in the end effector 10.

The shaft assembly 12 comprises a closure/jaw actuator 23, a firing/cutting member actuator 98 (FIG. 5), and an outer sheath 96. In some embodiments, the outer sheath 96 comprises the closure actuator 23. The outer sheath 96 comprises one or more contact electrodes on a distal end configured to interface with the end effector 10. The one or more contact electrodes are operatively coupled to the energy button 22 and an energy source (not shown).

The energy source may be suitable for therapeutic tissue treatment, tissue cauterization/sealing, as well as sub-therapeutic treatment and measurement. The energy button 22 controls the delivery of energy to the electrodes. As used throughout this disclosure, a button refers to a switch mechanism for controlling some aspect of a machine or a process. The buttons may be made out of a hard material such as usually plastic or metal. The surface may be formed or shaped to accommodate the human finger or hand, so as to be easily depressed or pushed. Buttons can be most often biased switches, even though many un-biased buttons (due to their physical nature) require a spring to return to their un-pushed state. Terms for the “pushing” of the button, may include press, depress, mash, and punch.

In some embodiments, an end effector 10 is coupled to the distal end of the shaft assembly 12. The end effector 10 comprises a first jaw member 16 a and a second jaw member 16 b. The first jaw member 16 a is pivotably coupled to the second jaw member 16 b. The first jaw member 16 a is pivotally moveable with respect to the second jaw member 16 b to grasp tissue therebetween. In some embodiments, the second jaw member 16 b is fixed. In other embodiments, the first jaw member 16 a and the second jaw member 16 b are pivotally movable. The end effector 10 comprises at least one electrode. The electrode is configured to deliver energy. Energy delivered by the electrode may comprise, for example, radiofrequency (RF) energy, sub-therapeutic RF energy, ultrasonic energy, and/or other suitable forms of energy. In some embodiments, a cutting member (not shown) is receivable within a longitudinal slot defined by the first jaw member 16 a and/or the second jaw member 16 b. The cutting member is configured to cut tissue grasped between the first jaw member 16 a and the second jaw member 16 b. In some embodiments, the cutting member comprises an electrode for delivering energy, such as, for example, RF and/or ultrasonic energy.

FIGS. 2 and 3 illustrate a side partial elevational view of the surgical instrument 2 with the left handle housing shroud 6 a removed. The handle assembly 4 comprises a plurality of components for actuating the surgical instrument 2, such as, for example, mechanism for affecting the closure of the jaws 16 a, 16 b of the end effector 10, deploying a cutting member within the end effector 10, and/or delivering energy to one or more electrodes coupled to the end effector 10. A two-stage trigger assembly 8 is configured to clamp and fire the end effector 10. The two-stage trigger assembly 8 comprises a two-stage trigger 9. The two-stage trigger 9 is coupled to one or more mechanisms for closing the jaws 16 a, 16 b of the end effector and deploying a cutting member therein.

In one embodiment, the two-stage trigger assembly 8 comprises a trigger plate 24 coupled to the two-stage trigger 9. Rotation of the two-stage trigger 9 rotates the trigger plate 24 about a rotation point defined by a rotation pin 25 a of a clamp assembly 25. Rotation of the trigger plate 24 to a first rotation causes rotation of a clamp plate 26. The clamp plate 26 is configured to transition the jaws 16 a, 16 b from an open position to a closed position. For example, in the illustrated embodiment, the clamp plate 26 is coupled to a yoke 32 by a toggle clamp 52. The toggle clamp 52 can be movably coupled to the clamp plate 26 by a pivot pin 57 c (FIG. 5), for example. Rotation of the clamp plate 26 drives the yoke 32 proximally. Proximal movement of the yoke 32 compresses a closure spring 42, causing proximal movement of the closure actuator 23 (FIG. 5). Proximal movement of the closure actuator 23 pivotally moves the first jaw member 16 a from an open position to a closed position with respect to the second jaw member 16 b, for example.

The two-stage trigger assembly 8 comprises a firing plate 28. Rotation of the trigger plate 24 beyond a predetermined rotation such as, for example, the first rotation, causes rotation of the firing plate 28. Rotation of the firing plate 28 deploys a cutting member within the end effector 10. For example, in the illustrated embodiment, the firing plate 28 comprises a sector gear operably coupled to a rack 36 through pinions 33 and 34. The firing plate 28 comprises a plurality of teeth configured to interface with the pinion 33. Rotation of the firing plate 28 rotates the pinions 33 and 34, driving the rack 36 distally. Distal movement of the rack 36 drives the cutting member actuator 98 distally, causing deployment of the cutting member within the end effector 10.

FIG. 4 illustrates one embodiment of the clamp assembly 25 of the two-stage trigger assembly 8. The trigger plate 24 is configured to interface with the clamp plate 26 during rotation of the two-stage trigger 9 from an initial position to a first rotation, for example. The trigger plate 24 is operably coupled to the clamp plate 26 by a floating pin 48. In certain instances, the trigger plate 24 may include a groove or an indentation 24 a in a side wall 24 b of the trigger plate 24. The groove 24 a may be configured to receive the floating pin 48. The floating pin 48 can be driven by the trigger plate 24 while the floating pin 48 is received in the groove 24 a. The floating pin 48 may slideably move within a pin track 56. The pin track 56 may be defined by, for example, a track plate 30 which may be fixedly coupled to at least one of the handle housing shrouds 6 a and 6 b, for example.

Rotation of the trigger plate 24, while the floating pin is received within the groove 24 a, may drive the floating pin 48 within the pin track 56. The floating pin 48 may drive rotation of the clamp plate 26 as the floating pin 48 is driven by the trigger plate 24 through a first section of the pin track 56. Rotation of the clamp plate 26 may drive the toggle clamp 52. The toggle clamp 52 is coupled to the yoke 32. Movement of the toggle clamp 52 causes proximal movement of the yoke 32, which compresses the closure spring 42. Compression of the closure spring 42 causes the jaws 16 a and 16 b to transition from an open position to a closed position, for example.

In certain instances, the pin track 56 comprises a bypass section 58. When the floating pin 48 reaches the bypass section 58 of the pin track 56, the floating pin 48 may move out of the groove 24 a and into the bypass section 58. Disengaged from the groove 24 a, the floating pin 48 may remain in the bypass section 58. In certain instances, the side wall 24 b may maintain the floating pin 48 in the bypass section 58 thereby preventing the clamp plate 26 from returning to a starting position of the clamp plate 26 corresponding to an unactuated initial position of trigger 9, for example. In other words, the trigger plate 24 may maintain the jaws 16 a and 16 b in the closed position by maintaining the floating pin 48 in the bypass section 56, for example. In certain instances, disengaging the floating member 48 from the groove 24 a may transition the two-stage trigger assembly 8 from a first stage of operation corresponding to closure or clamping of the jaws 16 a and 16 b to a second stage of operation corresponding to deployment of a cutting member, as described in greater detail below.

FIG. 5 illustrates an exploded view of the surgical instrument 2 illustrated in FIGS. 1-4. The surgical instrument 2 comprises a left handle housing 6 a and a right handle housing 6 b. The handle assembly 4 comprises a trigger assembly 8 having a two-stage trigger 9. The two-stage trigger 9 is coupled to a trigger plate 24. The trigger plate 24 is operably coupled to a clamp plate 26 by a floating pin 48. The floating pin 48 is slideably moveable within a pin track 56 defined by a track plate 30. The trigger 9 is further coupled to a firing plate 28 by a firing/trigger pin 50. The firing pin 50 is configured to slideably move within a firing pin path 60 defined by the firing plate 28. The trigger plate 24, the clamp plate 26, and the firing plate 28 are coupled to the handle assembly 4 by one or more pivot pins. In certain instances, the trigger plate 24 and/or the cam plate 54 are fixedly coupled to the trigger 9 by one or more pins such as, for example, the rotation pin 25 a and a pin 57 a, as illustrated in FIG. 5. In addition, the trigger plate 24 and/or the cam plate 54 may be movable with the trigger 9 relative to the pistol grip 18, for example. In certain instances, the pin plate 30 can be fixedly coupled to the handle assembly 4 by the pin 25 a and a pin 57 b, for example. The firing plate 28 operably interfaces with the rack 36 through the first pinion 33, and the second pinion 34. Rotation of the firing plate 28 causes the rack 36 to advance distally to deploy a cutting member within a longitudinal slot defined by the jaw assembly 16, for example. In certain instances, he trigger plate 24 and the clamp plate 26 are configured to rotate under the firing plate 28.

In some embodiments, a plunger 40 is configured to provide a physical stop to the two-stage trigger 9 at a first rotation. The plunger 40 is spring biased. The plunger 40 comprises a plunger pin 41 configured to interface with a cam path 68 defined by a cam plate 54. The cam plate 54 is operably coupled to the trigger plate 24. The cam plate 54 rotates in response to actuation of the two-stage trigger 9. The plunger pin 41 follows the cam path 68 during actuation of the two-stage trigger 9. The cam path 68 comprises a detent 72. When the plunger pin 41 reaches the detent 72, the plunger 40 springs into place and maintains the two-stage trigger 9 at the first rotation. The trigger 9 may be rotated proximally or distally from the first rotation. The two-stage trigger 9 is rotatable proximally, towards the pistol grip 18, to continue the firing stroke and deploy a cutting member within the end effector 10. The trigger is rotatable distally, away from the pistol grip 18, to release the jaws 16 a, 16 b of the end effector 10.

Referring back to FIGS. 2 and 3, the surgical instrument 2 is illustrated with the two-stage trigger 9 in an initial position. In the initial position, the two-stage trigger 9 is at a zero rotation position. The trigger plate 24, the clamp plate 26, and the floating pin 48 are in an initial position corresponding to the jaws 16 a, 16 b being in an open position. The floating pin 48 is located at the bottom of the pin track 56 defined by the track plate 30. The initial position of the two-stage trigger 9 further corresponds to the yoke 32 being in a distal-most position and the closure spring 42 having an initial compression. In some embodiments, the closure spring 42 is uncompressed when the yoke 32 is in a distal-most position. In other embodiments, the closure spring 42 comprises a pre-compressed spring having a first compression when the yoke 32 is in a distal-most position. The rack 36 is located in a proximal-most position.

The trigger 9 is coupled to the firing plate 28 by a firing pin 50 located within a firing pin path 60 defined by the firing plate 28. Rotation of the trigger 9 drives the firing pin 50 within the firing pin path 60. The firing pin path 60 comprises a non-firing portion 61 and a firing portion 62. When the firing pin 50 moves within the non-firing portion 61, the firing plate 28 remains stationary. As the trigger plate 24 continues to rotate and move the firing pin 50 into the firing portion 62, movement of the firing pin 50 rotates the firing plate 28 about a pivot point defined by a pivot pin 97 b.

In operation, a clinician positions a tissue section for treatment between the first and second jaw members 16 a, 16 b of the end effector 10. The clinician rotates the two-stage trigger 9 towards the pistol grip 18. Rotation of the two-stage trigger 9 rotates the trigger plate 24 and the cam plate 54 about an axis defined by the pivot pin 25 a. Rotation of the trigger plate 24 drives the floating pin 48 upward in the pin track 56. The floating pin 48 engages the clamp plate 26 and rotates the clamp plate 26 about the axis defined by the pivot pin 25 a. Rotation of the clamp plate 26 drives the toggle clamp 52 to move the yoke 32 proximally, which compresses the closure spring 42.

FIG. 6 illustrates the surgical instrument of FIG. 2 with the two-stage trigger 9 in a partially actuated position. The two-stage trigger 9 is illustrated at a rotation of about 7 degrees from the initial, or zero, position illustrated in FIG. 2. As shown in FIG. 6, rotation of the two-stage trigger 9 rotates the trigger plate 24 and drives the floating pin 48 within the pin track 56. The floating pin 48 has been driven upwards within the pin track 56. The floating pin 48 is interfaced with the clamp plate 26 and has partially rotated the clamp plate 26 to drive the toggle clamp 52. The movement of the toggle clamp 52 causes the yoke 32 to move proximally and compress the closure spring 42. The closure spring 42 is illustrated in a partially compressed position corresponding to a partial closure of the jaw assembly 16. In certain instances, the 7 degrees rotation of the trigger relative to the axis AA (See FIG. 2) may cause full closure of the jaw assembly 16 in the absence any material such as tissue, for example, between the jaws 16 a and 16 b. In certain instances, if tissue is captured between the jaws 16 a and 16 b, the 7 degrees rotation of the trigger relative to the axis AA may cause partial closure of the jaw assembly 16, for example.

The rotation of the trigger 9 drives the firing pin 50 within the firing pin path 60. The firing pin 50 moves within a first, non-firing portion 61 of the firing pin path 60 when the two-stage trigger 9 is rotated to the first rotation. As illustrated in FIG. 6, the firing pin 50 is illustrated within the non-firing portion 61 of the firing pin path 60, as the two-stage trigger 9 has not yet completed a first, or closing, stroke. Rotation of the two-stage trigger 9 further drives the cam plate 54 into contact with the plunger 40. As illustrated in FIG. 6, the plunger 40 contacts the cam path 68 defined by the cam plate 54 when the two-stage trigger 9 is actuated.

FIG. 7 illustrates the position of a cam plate 54 and a plunger 40 corresponding to the rotation of the trigger illustrated in FIG. 6. The cam plate 54 comprises a cam path 68 configured to allow the plunger pin 41 to stop and maintain an intermediate trigger position until an external force is applied. The plunger pin 41 defines a circumference configured to allow passage through the cam path 68. For example, in one embodiment, the plunger pin 41 defines a circumference comprising a diameter of 0.063″. The angles of the cam path 68 in combination with the plunger 40 spring rates are configured to enable a detent function. As shown in FIG. 7, a plunger pin 41 coupled to the plunger 40 is in contact with an angled portion 70 of the cam path 68. The plunger pin 41 contacts the uppermost end of the angled portion 70. As the cam plate 54 rotates in response to actuation of the two-stage trigger 9, the plunger pin 41 follows the cam path 68 and compresses the plunger 40. In one embodiment, the angled portion 70 of the cam path 68 comprises a first incline 70 a and a second incline 70 b. A surface of the first incline 70 a and a surface of the second incline 70 b are offset at a specific angle, such as, for example, 199.4°.

FIG. 8 illustrates the surgical instrument of FIG. 2 having the two-stage trigger 9 further actuated. In the illustrated embodiment, the two-stage trigger 9 comprises a rotation of greater than 7 degrees but less than 24 degrees. The continued rotation of the two-stage trigger 9 to the rotation illustrated in FIG. 8 further advances the trigger plate 24 to drive the floating pin 48 within the floating pin track 56 defined by the track plate 30. The floating pin 48 further drives the clamp plate 26 to drive the toggle clamp 52 and the yoke 32 proximally. In the illustrated embodiment, the yoke 32 has been driven to a proximal-most position and compresses the closure spring 42 to a maximum compression. The position of the yoke 32 and the compression of the closure spring 42 correspond to the jaws 16 a, 16 b of the end effector 10 being fully closed on a tissue section located therebetween. The trigger pin 50 has been driven to the uppermost section of the non-firing portion 61 of the firing pin path 60. The firing plate 28 remains in the initial position. FIG. 9 illustrates the plunger 40 and the cam plate 54 when the two-stage trigger 9 is at the rotation illustrated in FIG. 8. As shown in FIG. 9, the plunger pin 41 is located at the bottom of the angled portion 70 of the cam path 68. The plunger 40 has been compressed by the angled portion 70 of the cam path 68.

FIG. 10 illustrates the surgical instrument of FIG. 3 having the trigger actuated to a first rotation. In the illustrated embodiment, the first rotation corresponds to a rotation of about 24 degrees from the initial, or zero, position. Rotation of the two-stage trigger 9 to the first rotation advances the trigger plate 24 and moves the floating pin 48 into a bypass section 58 of the pin track 56. Movement of the floating pin 48 into the bypass section 58 causes the floating pin 48 to disengage with the trigger plate 24 and the clamp plate 26. Once the floating pin 48 enters the bypass section 58, continued rotation of the trigger plate 24 does not affect the clamp plate 26 and/or the jaws 16 a, 16 b of the end effector 10. The trigger plate 24 maintains the floating pin 48 in the bypass section 58 when the trigger plate 24 is further actuated. The toggle clamp 52 and the yoke 32 are maintained in a proximal-most position. In some embodiments, the yoke 32 moves slightly distally when the floating pin 48 enters the bypass section, causing the jaws 16 a, 16 b to reduce a force applied to a tissue section located therebetween. The clamp plate 26 rotates almost to center, but does not cross over center, allowing the clamp plate 26 to return to a starting position based on a force exerted by the closure spring 42 on the yoke 32 when the trigger 9 is released.

The rotation of the two-stage trigger 9 to the first rotation drives the trigger pin 50 to a transition position within the trigger pin track 60. Continued rotation of the two-stage trigger 9 drives the trigger pin 50 into the rotation section 62 of the trigger pin track 60. As can be seen in FIG. 10, the trigger plate 24 and the clamp plate 26 rotate beneath the firing plate 28 when rotated by actuation of the two-stage trigger 9. Rotation of the trigger 9 to the first rotation causes the plunger 40 to engage with a detent 72 of the cam path 68.

FIG. 11 illustrates the plunger 40 and the cam plate 54 when the trigger 9 has been rotated to the first rotation, as illustrated in FIG. 10. When the trigger 9 is rotated from a position less than the first rotation (for example, the position illustrated in FIG. 9) to the first rotation, the cam plate 54 rotates such that the plunger pin 41 disengages from the angled portion 70 of the cam path 68 and springs into contact with the detent 72. A vertical stop 74 (See FIG. 9) prevents over rotation of the trigger 9 before the plunger 40 springs into contact with the detent 72. In some embodiments, the vertical stop 74 comprises a first portion 74 a and a second portion 74 b. The first portion 74 a and the second portion 74 b are offset by a predetermined angle, such as, for example, 220.1°. The angle portion 70 of the cam path 68 and the vertical stop 74 are separated by a gap, such as, for example, a gap of 0.074″.

In some embodiments, the plunger 40 provides tactile and/or audible feedback to a clinician to indicate that the plunger pin 41 has moved into contact with the detent 72. The plunger 40 maintains the cam plate 54 and the trigger 9 at the first rotation until a predetermined force is applied to disengage the plunger 40 from the detent 72. In operation, a clinician may continue rotating the trigger 9 proximally to deploy the cutting member within the end effector 10 or may rotate the trigger 9 distally to open the jaws and return the surgical instrument 2 to the initial position illustrated in FIG. 3. The detent 72 comprises arms 73 a, 73 b that define the force necessary to deploy the cutting member and/or return the jaws 16 a, 16 b to an open position. The angle of the arms 73 a, 73 b determines the force necessary to disengage the plunger pin 41 from the detent 72 in a proximal or distal direction. In some embodiments, the first arm 73 a is offset from the second arm 73 b by an angle of, for example, 240.0°. Those skilled in the art will recognize that any suitable angle may be used. In some embodiments, the first arm 73 a and the vertical stop 74 define a first spacing therebetween and the second arm 73 b and the vertical stop 74 define a second spacing therebetween. The first spacing may comprise, for example, a spacing of about 0.074″. The second spacing may comprise, for example, a spacing of about 0.085″. The second arm 73 b and the angled portion 70 of the cam path 68 define a spacing therebetween, such as, for example, 0.080″ to allow the plunger pin 41 to pass unimpeded during a return stroke.

Rotation of the two-stage trigger 9 proximally deploys a cutting member within the end effector 10. Rotation of the trigger 9 beyond the first rotation disengages the plunger 40 from the detent 72. The force required to continue rotation of the two-stage trigger 9 to deploy the cutting member is defined by the arm 73 a of the detent 72 of the cam path 68. The trigger 9 rotates the trigger plate 24 to slideably move the trigger pin 50 within the rotation portion 62 of the trigger pin path 60. Movement of the trigger pin 50 within the rotation portion 62 causes the firing plate 28 to rotate about an axis defined by the pivot pin 57 c. Rotational movement of the firing plate 28 causes the pinions 33 and 34 to rotate to drive the rack 36 distally. Distal movement of the rack 36 deploys the cutting member distally within the end effector 10.

FIG. 12 illustrates the surgical instrument of FIG. 2 in a fully fired position. The two-stage trigger 9 of the two-stage trigger assembly 8 has been fully rotated proximally. In the illustrated embodiment, full rotation of the two-stage trigger 9 corresponds to a rotation of about 42 degrees from the initial position illustrated in FIG. 2. As shown in FIG. 12, the trigger plate 24 has been rotated under the firing plate 28. The firing pin 50 is located at the top of the firing pin path 60. Movement of the firing pin 50 within the rotation section 62 of the firing pin path 60 rotates the firing plate 28. Rotation of the firing plate 28 rotates the pinions 33 and 34, and advances the rack 36 distally. Distal movement of the rack 36 deploys the cutting member within the end effector 10. After the cutting member has been fully deployed, the clinician may release the two-stage trigger 9 to return the surgical instrument 2 to the initial position illustrated in FIG. 2. FIG. 12 illustrates the surgical instrument 2 in a fully fired position. In some embodiments, the mechanical advantage of the trigger 9 increases as the rotation of the trigger 9 increases.

In some embodiments, the plunger 40 is configured to bypass the cam path 68 during a return stroke. FIG. 13 illustrates a position of the plunger 40 with respect to the cam path 68 during a return stroke of the two-stage trigger assembly 8. The plunger 40 is spring biased, causing the plunger pin 41 to bypass the detent 72 of the cam path 68 during a return stroke. FIG. 13 illustrates the two-stage trigger 9 in a partially returned position. By bypassing the detent 72 of the cam path 68, the two-stage trigger assembly 8 provides a smooth return from the fully fired position illustrated in FIG. 12 to the initial position illustrated in FIG. 2. In some embodiments, the plunger pin 41 contacts the angled portion 70 of the cam path 68 to provide a dampening force to the return stroke of the two-stage trigger 9. The force of one or more springs, such as, for example, a firing spring 38 and/or the closure spring 52, automatically returns the trigger 9 to an initial position when the trigger 9 is released. In some embodiments, the clinician may manually rotate the trigger 9 to the initial position after firing.

In some embodiments, one or more elements of the two-stage trigger assembly 8 may comprise a lubricated and/or low friction material. For example, in some embodiments, one or more of the trigger plate 24, clamping plate 26, firing plate 28, track plat 30, cam plate 54 may comprise a lubricated and/or low friction material. In some embodiments, one or more of the pins, such as, for example, the plunger pin 41, the floating pin 48, and/or the firing pin 50 may comprise a lubricated and/or low friction material. Suitable low-friction materials for one or more plates and/or one or more pins comprise, for example, spinodal bronze, Nitronic 60, Cobalt 6B, Waukesha 88, Stellite, and/or Alloy 25. In some embodiments, one or more plates and/or one or more pins may comprise a lubricant coating, such as, for example, Nitrided, Titanium Nitride (TiN), Aluminum Titanium Nitride (AlTiN), and/or Malcomized coatings.

In some embodiments, the surgical instrument 2 comprises a two-stage bypass that allows the trigger assembly 8 to operate as a single stroke clamp and cut trigger. FIG. 14 illustrates one embodiment of the surgical instrument 2 comprising a two-stage bypass switch 46. The two-stage bypass switch 46 comprises a toggle switch that is slideable within the pistol grip 18 of the surgical instrument 2. When the two-stage bypass switch 46 is toggled to a bypass position, as illustrated in FIG. 14, the two-stage bypass switch 46 raises the plunger 40. By raising the plunger 40, the two-stage bypass switch 46 causes the plunger 40 to bypass the cam path 68 during a clamping and firing stroke. Bypassing the cam path 68 prevents the plunger from interfacing with the detent 72 and allows a single, uninterrupted trigger pull to clamp and fire the end effector 10 coupled to the surgical instrument 2. In certain instances, as illustrated in FIG. 14, a return spring 153 can be coupled to the plunger 40. The return spring 153 can be compressed as the toggle switch 46 raises the plunger 40 to the bypass position. Upon returning the toggle switch 46 to an initial position, the return spring 153 may decompress thereby returning the plunger 40 from the bypass position to a starting position, for example.

FIG. 15 illustrates the plunger 40 in a bypass position. As illustrated in FIG. 15, the two-stage bypass switch 46 raises the plunger 40 above the upper-most section of the angled portion 70 of the cam path 68. When the two-stage trigger 9 is actuated, the plunger 40 bypasses the angled portion 70 of the cam path 68 and the detent 72. When the cam path 68 is bypassed, the two-stage trigger assembly 8 operates as a single-stage trigger and allows a clinician to clamp and fire the surgical instrument 2 in a single motion.

FIG. 16 is a chart 100 illustrating, on the y axis 104, the Load (lb) on the trigger 9 at 2.25″ from the pivot pin 25 a versus, on the x axis 106, rotation angles of the trigger 9 starting with an initial unactuated position and ending with a final actuated position. As shown in FIG. 16, the force to fire 102 may increase up to a maximum force as the two-stage trigger 9 is rotated during a first rotation corresponding to a clamping stroke, for example. In certain instances, the force to fire 102 may begin to decrease during the first rotation upon reaching the maximum force. In the embodiment illustrated in FIG. 16, the jaws 16 a and 16 b are allowed to fully close unimpeded during the clamping stroke. As illustrated in FIG. 16, the spike at about 24 degrees corresponds to the plunger 40 interfacing with the detent 72 of the cam path 68 and the force required to overcome the arm 73 a of the detent 72 to continue rotation of the two-stage trigger 9.

FIG. 19 is a chart 130 illustrating, on the y axis 134, the Load (lb) on the trigger 9 at 2.25″ from the pivot pin 25 a versus, on the x axis 136, rotation angles of the trigger 9 up to a first rotation corresponding to a clamping stroke. In the embodiment illustrated in FIG. 19, the jaws 16 a and 16 b are only allowed to partially close during the clamping stroke. In certain instances, as illustrated in FIG. 19, the force to fire 132 may initially increase up to a maximum force as the two-stage trigger 9 is rotated during the first rotation. In certain instances, the force to fire 132 may begin to decrease during the first rotation upon reaching the maximum force, for example.

FIG. 20 is a chart 140 illustrating, on the y axis 144, the Load (lb) on the trigger 9 at 2.25″ from the pivot pin 25 a versus, on the y axis 146, rotation angles of the trigger 9 up to a first rotation corresponding to a clamping stroke. In the embodiment illustrated in FIG. 20, the jaws 16 a and 16 b are kept fully open during the clamping stroke. In certain instances, as illustrated in FIG. 20, the force to fire 142 may initially increase up to a maximum force as the two-stage trigger 9 is rotated during the first rotation. In certain instances, the force to fire 142 may begin to decrease during the first rotation upon reaching the maximum force, for example.

FIG. 17 is a graph 110 illustrating the mechanical advantage 114 of the two-stage trigger assembly 8 at various rotation angles 116 of the trigger 9 from an initial position to a first rotation corresponding to a clamping stroke of the two-stage trigger 9. As shown in FIG. 17, the mechanical advantage 110 of the two-stage trigger 9 increases as the two-stage trigger 9 is rotated towards the pistol grip 18. FIG. 18 is a graph 120 illustrating the mechanical advantage 124 of the two-stage trigger assembly 9 at various rotation angles 126 of the trigger 9 from the first rotation to a fully fired position. As shown in FIG. 18, the mechanical advantage 124 of the two-stage trigger 9 increases as the two-stage trigger 9 is rotated from the first position to a fully fired position.

FIG. 21 illustrates one embodiment of an energy delivery button 22 coupled to the handle assembly 4 of the surgical instrument 2. The energy delivery button 22 is configured to provide energy to one or more electrodes coupled to the end effector 10. In some embodiments, a clinician may actuate the energy delivery button 22 after clamping tissue within the end effector 10 and prior to deploying the cutting member within the end effector 10. For example, in some embodiments, when the plunger 40 interfaces with the detent 72 to indicate a fully clamped position of the end effector 10, the clinician actuates the energy delivery button 22 to provide therapeutic, sub-therapeutic, ultrasonic, and/or other energy to a tissue section clamped between the jaws 16 a, 16 b. After applying energy to the tissue section, the clinician actuates the trigger 9 to deploy the cutting member within the end effector 10 and cut the tissue section grasped between the first and second jaw members 16 a, 16 b.

FIG. 22 illustrates one embodiment of an energy circuit 266. The energy circuit 266 may be formed integrally with the handle assembly 4 of the surgical instrument 2. The energy circuit 266 comprises a generator connection 282, an end of stroke switch 284, and an energy switch connection 286. The generator connection 282 is configured to couple the energy circuit 266 to a generator. The generator may be located externally to the surgical instrument 2 and/or may be formed integrally with the handle assembly 4. The energy switch connection 286 couples the energy circuit 266 to the energy delivery button 22 of the surgical instrument 4. The end of stroke switch 284 is configured to prevent delivery of energy to the electrodes of the end effector 10 when the end effector 10 is not in a closed position.

FIG. 23 illustrates an energy system 88 of a surgical instrument, such as, for example, the surgical instrument 2 illustrated in FIGS. 1-15. The energy system 88 comprises an energy circuit, such as, for example, the energy circuit 266 illustrated in FIG. 22. A lockout bar 64 is configured to pivotably interface with the end of stroke switch 284 of the energy circuit 266. Proximal movement of the yoke 32 pivots the lockout bar 64 and actuates the end of stroke switch 284 of the energy circuit 266. When the yoke 32 is in an initial position, as illustrated in FIG. 23, the end of stroke switch 284 is in an open position. An open end of stroke switch 284 prevents delivery of energy to the end effector 10 when the energy delivery button 22 is actuated. When the end of stroke switch 284 is actuated, the energy circuit 266 is configured to provide energy to the electrodes of the end effector 10 when the energy button 22 is actuated. The energy circuit 266 is coupled to the generator (not shown) by a generator source wire 292 and a generator return wire 294. A handle source wire 298 and a handle return wire 299 coupled the energy circuit 66 to the energy delivery button 22 and the electrodes of the end effector 10.

In certain instances, as described above, the surgical instrument 2 may include an automatic energy lockout mechanism. The energy lockout mechanism can be associated with a closure mechanism of the surgical instrument 2. In certain instances, the energy lockout mechanism can be configured to permit energy delivery to the end effector 10 when the energy delivery button 22 is actuated if the jaws 16 a and 16 b are in an open configuration. In certain instances, the energy lockout mechanism may be configured to deny the energy delivery to the end effector 10 when the energy delivery button 22 is actuated if the jaws 16 a and 16 b are in a closed configuration. In certain instances, the energy lockout mechanism automatically transitions from permitting the energy delivery to denying the energy delivery when the jaws 16 a and 16 b are transitioned from the closed configuration to the open configuration, for example. In certain instances, the energy lockout mechanism automatically transitions from denying the energy delivery to permitting the energy delivery when the jaws 16 a and 16 b are transitioned from the open configuration to the closed configuration, for example.

In certain instances, as illustrated in FIG. 23, the lockout bar 64 may pivot about a pivot pin 57 d between a first position corresponding to an open configuration of the end of stroke switch 284, and a second position corresponding to the closed or actuated configuration of the end of stroke switch 284. Motion of the lockout bar 64 to the second position may actuate or close the end of stroke switch 284 of the energy circuit 266. In certain instances, the lockout bar 64 is biased in the first position by a spring 155, for example. In certain instances, the yoke 32 is proximally movable during a clamping stroke between an initial position, as illustrated in FIG. 23, and a final position, as illustrated in FIG. 12, for example. Proximal motion of the yoke 32 may compress the closure spring 42 causing the closure actuator 23 to be retracted, which causes the jaws 16 a and 16 b to be transitioned to a closed configuration. In certain instances, when the yoke 32 is in the initial position, as illustrated in FIG. 23, the lockout bar 64 is biased in the open position, and the end of stroke switch 284 is in an open position. In certain instances, during proximal motion of the yoke 32 toward the final position, the yoke 32 may engage the lockout bar 64 and overcome the biasing force of the spring 155 causing the lockout bar 64 to be transitioned from the first position to the second position, which causes the end of stroke switch 284 to be actuated or closed while the jaws 16 a and 16 b are in the closed configuration, for example. While in the closed or actuated position, the end of stroke switch 284 may permit delivery of energy to the end effector 10 when the energy delivery button 22 is actuated, as describe above.

Also as described above, releasing the trigger 9 may allow the yoke 32 to return from the final position to a starting position. As the yoke 32 returns to the initial position, the closure spring 42 and the return spring 41 may cooperate to return the closure actuator 23 to a starting position, which causes the jaws 16 a and 16 b to return an open configuration, for example. In addition, the yoke 32 may disengage from the lockout bar 64 as the yoke 32 is advanced to the initial position. In response, the spring 155 may cause the lockout bar 64 to return to the first position, which allows the end of stroke switch 284 to be returned to the open position thereby denying delivery of energy to the end effector 10 when the energy delivery button 22 is actuated, for example.

As described above, the two-stage trigger 9 can be moved relative to the pistol grip 18 during a first stage of operation to transition the end effector 10 from an open configuration to an approximated configuration to capture tissue between the jaws 16 a and 16 b, for example. In addition, the two-stage trigger 9 can be further moved relative to the pistol grip 18 during a second stage of operation to advance a cutting member to transect the captured tissue.

As described above, the trigger 9 can be selectively rotated toward the pistol grip 18 from an initial unactuated position defined by an axis AA (FIG. 2), for example, to a plurality of actuated positions at various angles with the axis AA. In certain instances, the trigger 9 can be selectively rotated toward the pistol grip 18 from the initial unactuated position to a first actuated position at a first angle with the axis AA, and further to a second actuated position at a second angle with the axis AA greater than the first angle, for example.

In certain instances, the trigger 9 can be selectively rotated toward the pistol grip 18 from the second actuated position to an intermediate actuated position at a third angle with the axis AA greater than the second angle, for example. In certain instances, the trigger 9 can be selectively rotated toward the pistol grip 18 from the intermediate actuated position to a final actuated position at a complete stroke of the trigger 9 at a final angle with the axis AA greater than the third angle of the intermediate actuated position, for example. In other instances, the trigger 9 can be selectively rotated away from the pistol grip 18 from the intermediate actuated position to allow the trigger 9 to return to the initial unactuated position.

In certain instances, as illustrated in FIG. 2, a return spring 151 can be pre-compressed to maintain the trigger 9 in the unactuated position and maintain the end effector 10 in the open configuration. Actuation of the trigger 9 from the unactuated position to an actuated position may further compress the return spring 151. In certain instances, releasing the trigger 9 at any actuated position prior to reaching the intermediate actuated position may cause the trigger 9 to return to the unactuated position as the return spring 151 decompresses to its initial pre-compressed state thereby returning the end effector 10 to the fully open configuration, for example.

In certain instances, the first angle of the first actuated position is about 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20% of the final angle of the final actuated position, for example. In at least one example, the first angle of the first actuated position is about 16.67% of the final angle of the final actuated position. In certain instances, the ratio of the first angle to the final angle is any value selected from a range of about 0.1, for example, to about 0.2, for example. Other suitable values of the ratio of the first angle to the final angle are contemplated by the present disclosure.

In certain instances, the trigger plate 24 and/or the cam plate 54 are fixedly attached to the trigger 9 and are movable with the trigger 9 about the pin 25 a, for example. In certain instances, actuation or rotation of the trigger 9 to the first actuated position causes the trigger plate 24 to motivate the floating pin 48 through the track 56 of the track plate 30. The floating pin 48, motivated by the trigger plate 24, may press against the clamp plate 26 thereby causing the clamp plate 26 to be rotated about the rotation pin 25 a. The rotation of the clamp plate 26 may cause the toggle clamp 52 to proximally move the yoke 32 a first distance “A”, for example. The proximal motion of the yoke 32 may cause the closure spring 42 to be compressed and the return spring 151 to be further compressed from its initial pre-compressed state to a fully compressed state, for example. In certain instances, compression of the closure spring 42 may cause the closure actuator 23 to transition the end effector 10 to the closed configuration.

As described above, the trigger plate 24 may include a groove or an indentation 24 a in a side wall 24 b of the trigger plate 24. The groove 24 a may be configured to receive the floating pin 48. The floating pin 48 can be driven by the trigger plate 24 while the floating pin 48 is received in the groove 24 a. The floating pin 48 may slideably move within the pin track 56. Rotation of the trigger plate 24, while the floating pin 48 is received in the groove 24 a, may drive the floating pin 48 within the pin track 56. The floating pin 48 may drive rotation of the clamp plate 26 as the floating pin 48 is driven by the trigger plate 24 through a first section of the pin track 56. Rotation of the clamp plate 26 may drive the toggle clamp 52 proximally. Movement of the toggle clamp 52 may cause proximal movement of the yoke 32, which may compress the closure spring 42. Compression of the closure spring 42 may cause the jaws 16 a and 16 b to be transitioned to the closed configuration, for example.

In certain instances, as illustrated in FIG. 8, the floating pin 48 can be at a transitory section of the pin track 56 while the trigger 9 is at the second actuated position, for example. The transitory section may reside between the first section of the track 56 and the bypass section 58 of the tack 56. In certain instances, actuation of the trigger 9 from the second actuated position to the intermediate actuated position may drive the floating pin 48 into the bypass section 58 thereby disengaging the floating pin 48 from the groove 24 a of the trigger plate 24 and terminating the first stage of operation of the two-stage trigger assembly 8, for example.

As described above, the trigger 9 can be maintained in the intermediate actuated position by maintaining the plunger pin 41 in locking engagement with the detent 72. In certain instances, further actuation of the trigger 9 from the intermediate actuated position toward the pistol grip 18 may cause rotation of the firing plate 28 during the second stage of operation of the two-stage trigger assembly 8 thereby causing deployment of the cutting member. Alternatively, actuation of the trigger 9 from the intermediate actuated position away from the pistol grip 18 may allow the trigger 9 to return to the initial unactuated position.

In certain instances, the trigger plate 24 may include a catching member 24 c, which may protrude from the side wall 24 b, for example. The catching member 24 c may be configured to catch the floating pin 48 as the trigger 9 is allowed to return to the initial actuated position. In certain instances, the catching member 24 c may return the floating pin 48 into the groove 24 a of the trigger plate 24 by slidably moving the floating pin 48 from the bypass section 58 to the first section of the pin track 56. While being held in the bypass section 58, the floating pin 48 may prevent the clamp plate 26 from returning to a starting position, which may cause the jaws 16 a and 16 b to remain in a closed configuration, for example.

Returning the floating pin 48 to the groove 24 a may free the floating pin 48 to move with the trigger plate 24. In addition, the closure spring 42 and/or the return spring 151, now free to decompress, at least partially, may provide the force required to return the trigger 9 to the unactuated position. In certain instances, the yoke 32 is advanced distally to a starting position corresponding to the initial actuated position of the trigger 9 as the closure spring 42 and/or the return spring 151 are allowed to decompress. In turn, the toggle clamp 52, the clamping plate 26, the floating pin 48, the trigger plate 24 can also be returned to their starting positions, for example. In addition, the return spring 151 may advance the closure actuator 23 to a starting position allowing the jaws 16 a and 16 b to return to the open configuration.

In certain instances, where the jaws 16 a and 16 b are allowed to fully close unimpeded, the actuation of the trigger 9 to the first actuated position may cause the jaw assembly 16 to reach full closure at the first actuated position as the yoke 32 reaches the end of the first distance A, for example. In certain instances, the first distance A is any value selected from a range of about 0.200″, for example, to about 0.400″, for example. In at least one example, the first distance A is about 0.272, for example. Other suitable values of the distance A are contemplated by the present disclosure.

In certain instances, the third angle of the intermediate actuated position is about 54%, 55%, 56%, 57%, 58%, 59%, or 60% of the final angle of the final actuated position, for example. In at least one example, the third angle of the intermediate actuated position is about 57.14% of the final angle of the final actuated position. In certain instances, the ratio of the third angle to the final angle is any value selected from a range of about 0.5, for example, to about 0.7, for example. Other suitable values of the ratio of the third angle to the final angle are contemplated by the present disclosure.

In certain instances, the intermediate actuated position can be defined by the stop 74, as illustrated in FIG. 11, and the second actuation position can be defined by the second incline 70 b of the angled portion 70, for example. As the trigger 9 is actuated past the first actuated position toward the second actuated position, the plunger pin 41 is guided through the cam path 68 by the angle portion 70, as illustrated in FIG. 8. A pre-compressed plunger spring 154, which maintains the plunger 40 in a biased state, can be further compressed by a pressure applied by angled portion 70 against the plunger pin 41 as the angled portion 70 is moved relative to the plunger pin 41, for example.

In certain instances, in the second actuated position of the trigger 9, the plunger pin 41 is pressed against the second incline 70 b of the angled portion 70. Releasing the trigger 9 at the second actuated position may allow the trigger 9 to return to the initial unactuated position and the end effector 10 to the open configuration as the return spring 151 at least partially decompresses. Alternatively, further actuation of the trigger 9 past the second actuated position may cause the plunger pin 41 to separate from the second incline 70 b of the angled portion 70 and engage the stop 74, for example. As the plunger pin 41 is released from contact with the angled portion 70, the plunger spring 154 is partially decompressed springing the plunger pin 41 into engagement with the stop 74. The engagement of the plunger pin 41 with the stop 74 may provide a first auditory and/or tactile feedback. Slightly alleviating the pressure on the trigger 9 may allow the plunger pin 41 to be released from the stop 74 and further sprung into engagement with the detent 72, for example. The engagement of the plunger pin 41 with the detent 72 may provide a second auditory and/or tactile feedback. Depending on the position and angle of the stop 74, in certain instances, if the user continued to press the trigger 9 after the first feedback is triggered without alleviating the pressure, the plunger pin 41 may continue to be pressed against the stop 74 resisting further retraction of the trigger 9 toward the pistol grip 18 until the necessary pressure alleviation is realized. This can provide a precautionary step to prevent a user from accidentally actuating the trigger 9 past the closure stage and into the firing stage, which may help prevent unintended deployment of the cutting member.

Further to the above, the springing plunger pin 41 may be caught by the detent 72 at the intermediate actuated position, which may cause the trigger 9 to remain locked in the intermediate position and the end effector 10 to remain in the closed configuration. An external force may be required to release the trigger 9 from the intermediate actuated position. To continue actuating the trigger 9 from the intermediate position, a sufficient force may need to be applied against the trigger 9 to force the plunger pin 41 out of locking engagement with the detent 72. As described above, the detent 72 may include arms 73 a, 73 b that define the force necessary to disengage the plunger pin 41 from the detent 72. The position of the detent 72 and/or the angle of the arms 73 a and/or 73 b may determine the force necessary to disengage the plunger pin 41 from the detent 72.

Once the trigger 9 is locked in the intermediate position, the user is presented with three choices. The user may allow the trigger 9 to remain in the locked intermediate position. Alternatively, the user may move the trigger 9 away from the pistol grip 18 to allow the trigger 9 to return to the initial actuated position. Alternatively, the user may move the trigger 9 toward the pistol grip 18 to continue actuating the trigger 9 toward the final actuated position.

In certain instances, at the intermediate actuated position, if the trigger 9 is moved away from the pistol grip 18, the plunger pin 41 may exit or disengage the detent 72 from the side of the arm 73 b. In such instances, the trigger 9 may return to the unactuated position and the end effector 10 may return to the open configuration, for example. In other instances, at the intermediate actuated position, if the trigger 9 is moved toward the pistol grip 18, the plunger pin 41 may exit or disengage the detent 72 from the side of the arm 73 a. In such instances, continued actuation of the trigger 9 to the final actuated position, as illustrated in FIG. 12, may result in deployment of the cutting member, as described above.

As described above, the plunger 40 can be configured to bypass the cam path 68 during a return stroke. FIG. 13 illustrates a position of the plunger 40 with respect to the cam path 68 during a return stroke of the two-stage trigger assembly 8. As described above, the plunger 40 can be spring biased by the plunger spring 154, which may cause the plunger pin 41 to bypass the detent 72 of the cam path 68 during a return stroke. FIG. 13 illustrates the two-stage trigger 9 in a partially returned position. By bypassing the detent 72 of the cam path 68, the two-stage trigger assembly 8 provides a smooth return from the final actuated position illustrated in FIG. 12 to the initial actuated illustrated in FIG. 3. In some instances, as illustrated in FIGS. 12 and 12A, the plunger pin 41 may engage the angled portion 70 on a first side 156 (See FIG. 12A) of the angled portion 70 of the cam path 68, which may provide a dampening force to the return stroke of the two-stage trigger 9. The plunger pin 41 may pass along a second side 158 of the angled portion 70 as the trigger 9 is actuated toward the intermediate actuated position, as described above.

Referring to FIG. 12A, an exemplary embodiment of the cam path 68 is depicted. A plurality of possible positions of the plunger pin 41 along the cam path 68 are illustrated in FIG. 12A. As described above, the spatial relationship between the angled portion 70, the stop 74, and/or the detent 72 may control the position of the plunger pin 41 along the cam path 68 during actuation of the trigger 9. The reader will appreciate that the plurality of positions of the plunger pin 41 can be defined along an axis BB extending along a length of the plunger 40, as illustrated in FIG. 7. Motion of the cam plate 54 with the trigger 9 may cause the angled portion 70, the stop 74, and/or the detent 72 to apply camming forces against the plunger pin 41, which may change the position of the plunger pin 41 along the axis BB, for example.

In certain instances, as described above, the actuation of the trigger 9 from the first actuated position to second actuated position may rotate the cam plate 54 thereby causing the plunger pin 41 to be guided through the cam path 68 along the second side 158 of the angled portion 70. As the cam plate 54 is rotated with the trigger 9 from the first actuated position to the second actuated position, the plunger pin 41 may be initially pressed against a camming surface 160 of the of the first incline 70 a, and then pressed against a camming surface 162 of the second incline 70 b. In certain instances, as illustrated in FIG. 12A, the camming surface 160 of the first incline 70 a can be offset from the camming surface 162 of the second incline 70 b by an angle A.

In certain instances, the angle A can be any value selected from a range of about 190.0° to about 210.0°, for example. In certain instances, the angle A can be any value selected from a range of about 195.0° to about 205.0°, for example. In certain instances, the angle A can be any value selected from a range of about 197.0° to about 202.0°, for example. In certain instances, the angle A can be any value selected from a range of about 199.0° to about 200.0°, for example. In certain instances, as described above, the angle A can be about 199.4°, for example. Other suitable values for the angle A are contemplated by the present disclosure.

As described above, the actuation of the trigger 9 from the second actuated position toward the intermediate actuated position may cause the plunger pin 41 to be released from contact with the second incline 70 b of the angled portion 70 and sprung into engagement with the with the stop 74, as illustrated in FIG. 12A. As described above, the stop 74 may comprise a first portion 74 a and a second portion 74 b. In certain instances, the first portion 74 a may include a camming surface 164, and the second portion 74 b may include a second camming surface 166. In certain instances, the first camming surface 164 may be offset from the second camming surface 166 by an angle B, for example. The angle B may define a corner 168 between the first camming surface 164 and the second camming surface 166. The corner 168 can be configured to temporarily receive the plunger pin 41 after the plunger pin 41 is released from the angled portion 70. In certain instances, the plunger pin 41, after being received by the corner 168, may slide relative to the first camming surface 164 until the plunger pin 41 is released from contact with the stop 74 and sprung into locking engagement with the detent 72 at the intermediate actuated position, for example. In certain instances, the angle B can configured such that the corner 168 may continue to block the springing of the plunger pin 41 toward the detent 72 until the pressure applied to the trigger 9 is slightly alleviated, for example. As described above, a first auditory and/or tactile feedback may be realized when the plunger pin 41 contacts the stop 74, and a second auditory and/or tactile feedback may be realized when the plunger pin 41 contacts the detent 72, for example.

In certain instances, the stop 74 can be dimensioned and/or positioned relative to the angled portion 70 and/or the detent 72 to prevent the plunger pin 41 from bypassing the detent 72 after the plunger pin 41 is released from the angled portion 70. Said another way, the stop 74 can be configured to guide the springing of the plunger pin 41 from the angled portion 70 into locking engagement with the detent 72 at the intermediate actuated position. In at least one example, as illustrated in FIG. 12A, the second portion 74 b may extend beyond the second incline 70 b to prevent the plunger pin 41 from passing underneath the second portion 74 b and ultimately missing the detent 72. In certain instances, the second portion 74 b may comprise a distal end portion 174 that extends beyond a distal end portion 170 of the second incline 70 b, for example. In certain instances, the distal end portion 174 can be offset from the distal end portion 170 by a distance D1, as illustrated in FIG. 12A. In certain instances, the distance D1 can be any value selected from a range of about 0.005″ to about 0.030″, for example. In certain instances, the distance D1 can be any value selected from a range of about 0.007″ to about 0.010″, for example. In certain instances, the distance D1 can be any value selected from a range of about 0.008″ to about 0.009″, for example. In certain instances, the distance D1 can be 0.0085, for example. Other suitable values for the distance D1 are contemplated by the present disclosure.

Further to the above, in order for the plunger pin 41 to be received by the corner 168, the plunger pin 41 may be dimensioned to pass between the second incline 70 b of the angled portion 70 and the second portion 74 b of the stop 74, for example. In certain instances, the plunger pin 41 may be smaller than a minimum distance D2 between the second incline 70 b of the angled portion 70 and the second portion 74 b, for example. In certain instances, the minimum distance D2 extends between an end portion 172 of the second incline 70 b of the angled portion 70 and the second portion 74 b. In certain instances, the plunger pin 41 may be smaller than the minimum distance D2 by a percentage selected from a range of about 1% to about 30%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D2 by a percentage selected from a range of about 5% to about 20%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D2 by a percentage selected from a range of about 13% to about 18%, for example. In certain instances, the plunger pin 41 may be 15% smaller than the minimum distance D2, for example.

In certain instances, the minimum distance D2 can be any value selected from a range of about 0.050″ to about 0.100″, for example. In certain instances, the minimum distance D2 can be any value selected from a range of about 0.060″ to about 0.080″, for example. Preferably, the minimum distance D2 can be any value selected from a range of about 0.072″ to about 0.076″, for example. In at least one example, the minimum distance D2 can be 0.074″. In certain instances, the plunger pin 41 may comprise a circular outer perimeter (See FIG. 12A) comprising a diameter D in the range of about 0.040″ to about 0.080″, for example. In certain instances, the diameter D of the plunger pin 41 may be in the range of about 0.045″ to about 0.075″, for example. In certain instances, the diameter D of the plunger pin 41 may be in the range of about 0.050″ to about 0.070″, for example. In at least one example, as described above, the diameter D of the plunger pin 41 may be 0.063″, for example. Other suitable values for the diameter D of the plunger pin 41 are contemplated by the present disclosure.

In certain instances, the angle B can be any value selected from a range of about 210.0° to about 230.0°, for example. In certain instances, the angle B can be any value selected from a range of about 215.0° to about 225.0°, for example. In certain instances, the angle B can be any value selected from a range of about 218.0° to about 222.0°, for example. In certain instances, the angle B can be any value selected from a range of about 219.0° to about 221.0°, for example. In certain instances, as described above, the angle B can be 220.1°, for example. Other suitable values for the angle B are contemplated by the present disclosure.

As described above, the detent 72 may comprise arms 73 a and 73 b that define the force necessary to release the trigger 9 from the intermediate actuated position. In certain instances, as illustrated in FIG. 12A, the arm 73 a may determine, at least in part, the force necessary to disengage the plunger pin 41 from the detent 72 as the trigger 9 is actuated toward the pistol grip 18 to deploy the cutting member, for example. In certain instances, as illustrated in FIG. 12A, the arm 73 b may determine, at least in part, the force necessary to disengage the plunger pin 41 from the detent 72 as the trigger is actuated away from the pistol grip 18 to allow the jaws 16 a and 16 b to return to the open configuration, for example. In some instances, the first arm 73 a may comprise a first camming surface 176, and the second arm 73 b may comprise a second camming surface 178. In certain instances, the first camming surface 176 is offset from the second camming surface 178 by an angle C. As illustrated in FIG. 12A, the angle C may define a corner 180 between the arms 73 a and 73 b, which can be configured to receive the plunger pin 41 at the intermediate actuated position, for example.

In certain instances, the angle C can be any value selected from a range of about 230.0° to about 250.0°, for example. In certain instances, the angle C can be any value selected from a range of about 235.0° to about 245.0°, for example. In certain instances, the angle C can be any value selected from a range of about 238.0° to about 242.0°, for example. In certain instances, the angle C can be any value selected from a range of about 239.0° to about 241.0°, for example. In certain instances, as described above, the angle C can be 240.0°, for example. Other suitable values for the angle B are contemplated by the present disclosure.

Further to the above, if the trigger 9 is actuated toward the pistol grip 18 to release the plunger pin 41 from the detent 72 at the intermediate actuated position, the plunger pin 41 may pass between the arm 73 a of the detent 72 and the first portion 74 a of the stop 74, as illustrated in FIG. 12A. In certain instances, the plunger pin 41 may be dimensioned to pass between the arm 73 a of the detent 72 and the first portion 74 a of the stop 74, as illustrated in FIG. 12A.

In certain instances, as illustrated in FIG. 12A, the plunger pin 41 may be smaller than a minimum distance D3 between the arm 73 a of the detent 72 and the first portion 74 a of the stop 74, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D3 by a percentage selected from a range of about 1% to about 30%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D3 by a percentage selected from a range of about 5% to about 20%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D3 by a percentage selected from a range of about 13% to about 18%, for example. In certain instances, the plunger pin 41 may be 15% smaller than the minimum distance D3, for example.

In certain instances, the minimum distance D3 can be any value selected from a range of about 0.050″ to about 0.100″, for example. In certain instances, the minimum distance D3 can be any value selected from a range of about 0.060″ to about 0.080″, for example. Preferably, the minimum distance D3 can be any value selected from a range of about 0.072″ to about 0.076″, for example. In at least one example, the minimum distance D3 can be 0.074″. Other suitable values for the minimum distance D3 are contemplated by the present disclosure.

Further to the above, if the trigger 9 is actuated away from the pistol grip 18 to release the trigger 9 from the detent 72 at the intermediate actuated position, the plunger pin 41 may pass between the arm 73 b of the detent 72 and the first portion 74 a of the stop 74, for example. In addition, the plunger pin 41 may pass between the arm 73 b of the detent 72 and the first incline 70 a of the angled portion 70, as illustrated in FIG. 12A.

In certain instances, the plunger pin 41 may be smaller than a minimum distance D4 between the arm 73 b of the detent 72 and the first portion 74 a of the stop 74, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D4 by a percentage selected from a range of about 1% to about 30%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D4 by a percentage selected from a range of about 5% to about 20%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D4 by a percentage selected from a range of about 13% to about 18%, for example. In certain instances, the plunger pin 41 may be 15% smaller than the minimum distance D4, for example.

In certain instances, the minimum distance D4 can be any value selected from a range of about 0.050″ to about 0.100″, for example. In certain instances, the minimum distance D4 can be any value selected from a range of about 0.060″ to about 0.080″, for example. In certain instances, the minimum distance D4 can be any value selected from a range of about 0.083″ to about 0.087″, for example. Preferably, the minimum distance D4 can be any value selected from a range of about 0.073″ to about 0.077″, for example. In at least one example, the minimum distance D4 can be 0.074″. In at least one example, the minimum distance D4 can be 0.075″. Other suitable values for the minimum distance D4 are contemplated by the present disclosure.

In certain instances, as illustrated in FIG. 12A, the plunger pin 41 may be smaller than a minimum distance D5 between the arm 73 b of the detent 72 and the first incline 70 a of the angled portion 70 a, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D5 by a percentage selected from a range of about 1% to about 30%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D5 by a percentage selected from a range of about 5% to about 20%, for example. In certain instances, the plunger pin 41 may be smaller than the minimum distance D5 by a percentage selected from a range of about 13% to about 18%, for example. In certain instances, the plunger pin 41 may be 15% smaller than the minimum distance D5, for example.

In certain instances, the minimum distance D5 can be any value selected from a range of about 0.050″ to about 0.100″, for example. In certain instances, the minimum distance D5 can be any value selected from a range of about 0.060″ to about 0.090″, for example. In certain instances, the minimum distance D5 can be any value selected from a range of about 0.078″ to about 0.082″, for example. Preferably, the minimum distance D5 can be any value selected from a range of about 0.065″ to about 0.085″, for example. Preferably, the minimum distance D5 can be any value selected from a range of about 0.068″ to about 0.082″, for example. In at least one example, the minimum distance D5 can be 0.074″. In at least one example, the minimum distance D5 can be 0.070″. In at least one example, the minimum distance D5 can be 0.080″. Other suitable values for the minimum distance D5 are contemplated by the present disclosure.

While the examples herein are described mainly in the context of electrosurgical instruments, it should be understood that the teachings herein may be readily applied to a variety of other types of medical instruments. By way of example only, the teachings herein may be readily applied to tissue graspers, tissue retrieval pouch deploying instruments, surgical staplers, ultrasonic surgical instruments, etc. It should also be understood that the teachings herein may be readily applied to any of the instruments described in any of the references cited herein, such that the teachings herein may be readily combined with the teachings of any of the references cited herein in numerous ways. Other types of instruments into which the teachings herein may be incorporated will be apparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

The disclosed embodiments have application in conventional endoscopic and open surgical instrumentation as well as application in robotic-assisted surgery.

Embodiments of the devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. Embodiments may, in either or both cases, be reconditioned for reuse after at least one use. Reconditioning may include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, embodiments of the device may be disassembled, and any number of the particular pieces or parts of the device may be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, embodiments of the device may be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device may utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

By way of example only, embodiments described herein may be processed before surgery. First, a new or used instrument may be obtained and if necessary cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta or gamma radiation, ethylene oxide, or steam.

It is worthy to note that any reference to “one aspect,” “an aspect,” “one embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in one embodiment,” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same aspect.

One skilled in the art will recognize that the herein described components (e.g., operations), devices, objects, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific exemplars set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects should not be taken as limiting.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations are not expressly set forth herein for sake of clarity.

The herein described subject matter sometimes illustrates different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected,” or “operably coupled,” to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being “operably couplable,” to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and/or physically interacting components, and/or wirelessly interactable, and/or wirelessly interacting components, and/or logically interacting, and/or logically interactable components.

Some aspects may be described using the expression “coupled” and “connected” along with their derivatives. It should be understood that these terms are not intended as synonyms for each other. For example, some aspects may be described using the term “connected” to indicate that two or more elements are in direct physical or electrical contact with each other. In another example, some aspects may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, also may mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other.

In some instances, one or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise.

While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true scope of the subject matter described herein. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.”

With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.

In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.

Various aspects of the subject matter described herein are set out in the following numbered clauses: 

What is claimed is:
 1. A surgical instrument, comprising: a handle assembly comprising: a trigger; a push plate coupled to the trigger, wherein actuation of the trigger rotates the push plate; a clamp plate operably coupled to the push plate, wherein actuation of the trigger to a first rotation rotates the clamp plate; and a firing plate operably coupled to the push plate, wherein actuation of the trigger between the first rotation and a second rotation rotates the firing plate; a shaft assembly comprising a proximal end and a distal end, wherein the shaft assembly is coupled to the handle assembly at the proximal end; and an end effector coupled to the distal end of the shaft assembly, the end effector comprising: a jaw assembly, comprising: a first jaw member; and a second jaw member, wherein rotation of the clamp plate transitions the jaw assembly between an open configuration and an approximated configuration by moving at least one of the first jaw member and the second jaw member relative to the other one of the first jaw member and the second jaw member; and a cutting member deployable in response to rotation of the firing plate.
 2. The surgical instrument of claim 1, further comprising a floating pin operably coupled to the clamp plate, wherein the floating pin is configured to move within a floating pin path comprising a bypass section
 3. The surgical instrument of claim 2, wherein rotation of the trigger causes the push plate to move the floating pin within the floating pin path, wherein the push plate comprises a groove, and wherein the floating pin is disengaged from the groove of the push plate by entering the bypass section.
 4. The surgical instrument of claim 3, wherein the floating pin is maintained in the bypass section during rotation of the trigger from the first rotation to the second rotation.
 5. The surgical instrument of claim 4, wherein the clamp plate is movably coupled to a toggle member.
 6. The surgical instrument of claim 5, further comprising a yoke movably coupled to the toggle member, wherein the toggle member is configured to drive the yoke proximally, and wherein the jaw assembly is transitioned to the approximated configuration in response to proximal movement of the yoke.
 7. The surgical instrument of claim 1, further comprising a trigger pin coupled to the push plate, wherein the trigger pin is configured to move within a trigger pin path defined by the firing plate, and wherein rotation of the trigger slideably moves the trigger pin within the trigger pin path.
 8. The surgical instrument of claim 7, wherein the trigger pin path comprises: a first section; and a second section, wherein the firing plate remains stationary as the trigger pin is slidably moved through the first section, and wherein the firing plate is rotated as the trigger pin slidably moves through the second section.
 9. The surgical instrument of claim 7, wherein a mechanical advantage of the trigger changes as the trigger pin is slidably moved through the trigger pin path.
 10. The surgical instrument of claim 1, wherein at least one of the push plate, the clamp plate, and the firing plate comprises a low-friction material.
 11. The surgical instrument of claim 1, further comprising a rack and pinion assembly operably coupled to the firing plate.
 12. The surgical instrument of claim 11, wherein the rack and pinion assembly is configured to deploy the cutting member in response to rotation of the firing plate.
 13. A multi-stage trigger assembly for use with a surgical instrument, wherein the surgical instrument includes a closure assembly and a firing assembly, and wherein the multi-stage trigger assembly comprises: a trigger comprising a cam path including a detent, the trigger actuatable from an initial unactuated position to a first actuated position, an intermediate actuated position, and a final actuated position, wherein the trigger interfaces with the closure assembly in a first stage of operation defined between the initial unactuated position and the intermediate actuated position, wherein the trigger interfaces with the firing assembly in a second stage of operation defined between the intermediate actuated position and the final actuated position, and wherein the trigger is disengaged from the closure assembly in the second stage of operation; and a plunger comprising a plunger pin configured to interface with the cam path, wherein the plunger pin engages the cam path at the first actuated position, and wherein the plunger pin follows the cam path to locking engagement with the detent at the intermediate actuated position.
 14. The multi-stage trigger assembly of claim 13, wherein the cam path comprises a sliding profile, wherein the plunger engages the sliding profile at the first actuated position.
 15. The multi-stage trigger assembly of claim 14, wherein the sliding profile comprises a first portion and a second portion, wherein the first portion and the second portion define an angle therebetween.
 16. The multi-stage trigger assembly of claim 15, wherein the angle defined by the first portion and the second portion is selected from a range of about 197 degrees to about 202 degrees.
 17. The multi-stage trigger assembly of claim 14, wherein the cam path comprises a stop profile configured to guide the plunger pin toward the detent.
 18. The multi-stage trigger assembly of claim 17, wherein the stop profile is offset from the sliding profile by a distance selected from a range of about 0.007″ to about 0.010″.
 19. The multi-stage trigger assembly of claim 17, wherein the stop profile comprises a first portion and a second portion, wherein the first portion and the second portion define an angle therebetween, and wherein the angle defined by the first portion and the second portion is selected from a range of about 218 degrees to about 222 degrees.
 20. The multi-stage trigger assembly of claim 13, further comprising a firing plate operably coupled to the firing assembly, the firing plate interfacing with the trigger in the second stage of operation, wherein actuation of the trigger to the final actuated position in the second stage of operation rotates the firing plate.
 21. The multi-stage trigger assembly of claim 13, further comprising a clamp plate operably coupled to the closure assembly, the clamp plate interfacing with the trigger in the first stage of operation, wherein actuation of the trigger to the first actuated position in the first stage of operation rotates the clamp plate.
 22. The multi-stage trigger assembly of claim 13, wherein the detent comprises a first arm and a second arm, wherein the first arm sets a first force required to free the plunger pin from the first arm to continue rotation of the trigger to the final actuated position, and wherein the second arm sets a second force required to free the plunger pin from the second arm to permit the trigger to return to the initial unactuated position.
 23. The multi-stage trigger assembly of claim 22, wherein the first arm and the second arm define an angle therebetween, and wherein the angle defined by the first arm and the second arm is selected from a range of about 238 degrees to about 242 degrees.
 24. The multi-stage trigger assembly of claim 13, further comprising a toggle switch, wherein the toggle switch is movable between a first position and a second position, and wherein transitioning the toggle switch from the first position to the second position causes the plunger pin to bypass the cam path.
 25. A surgical instrument, comprising: an end effector, comprising: at least one electrode; a first jaw member; and a second jaw member, wherein the end effector is transitionable between an open configuration and an approximated configuration by moving at least one of the first jaw member and the second jaw member relative to the other one of the first jaw member and the second jaw member; and a handle assembly, comprising: a closure trigger movable between an unactuated position and an actuated position; a closure member operably coupled to the closure trigger, the closure member movable between a first position and a second position, wherein actuation of the closure trigger from the unactuated position to the actuated position moves the closure member from the first position to the second position; an energy trigger actuatable to deliver energy to the at least one electrode; and an energy lockout switch transitionable between an open state and a closed state, wherein the energy lockout switch is biased in the open state, wherein in the open state, the energy lockout switch denies energy delivery to the at least one electrode when the energy trigger is actuated, wherein in the closed state, the energy lockout switch permits energy delivery to the at least one electrode when the energy trigger is actuated, wherein moving the closure member from the first position to the second position transitions the end effector from the open configuration to the approximated configuration, and transitions the energy lockout switch from the open state to the closed state. 